Rope swivel sockets for detachably connecting cables to various tools in wells are well known in the prior art. One such prior art device is disclosed in U.S. Pat. No. 2,995,791, issued to Clegg. This patent discloses a side opening socket body, a slide for the closing of the side opening, a cable attached mandrel or swivel, and a top locking nut which engages screw-threads on the upper reduced terminals of the socket body and slide. Immediately below the locking nut and above an enlarged tapered shoulder on the socket body, the Clegg device includes a fishing neck having wickers formed thereon to be engaged by a fishing tool or grapple.
The placement of the locking nut above the wickers in the Clegg device presents problems. The nut is frequently damaged during fishing operations and the nut can also interfere with the fishing equipment. Also, the small diameter locking nut at the top of the Clegg socket assembly is too small to pass over the swivel when it is desired to use the swivel alone and without the socket body with smaller size tools. Consequently, with the Clegg device, when such tool changes are necessary, the cable attached to the swivel must be cut to allow separation of the nut therefrom, and then the cable must be rebabbitted inside of the swivel or mandrel. Such operations are time-consuming and costly, sometimes requiring up to three hours.
In view of the above, the present invention has for its object to significantly improve on the convenience and utility of the prior art, and in particular, to improve on the rope swivel socket arrangement in the above-referenced Clegg U.S. Pat. No. 2,995,791. More particularly, by means of the present invention, the necessity for severing the drilling cable as required in the Clegg structure is eliminated, and the damaging of the locking nut during fishing operations and the interference of the nut with fishing tools is completely eliminated. These very important improvements are achieved in the invention by a simple relocation of the assembly locking nut to a lower elevation on the assembly well below the fishing neck and the wickers, and by increasing the size of the locking nut so that it can pass over the swivel when it is desired to separate the swivel from the socket body and use the swivel alone with an appropriate tool.
Other features and advantages of the invention will become apparent during the course of the following detailed description.
The following additional known U.S. patents are also made of record herein under the provisions of 37 CFR 1.56 and none of these patents shows or suggests the above -discussed improvements: U.S. Pat. Nos. 1,432,117; 1,453,138; 1,547,195; 1,617,664; 2,123,783; 2,152,233; 2,483,944.